I think the trailer got everyone's hopes a little too high (it being awesome and all). I got disappointed myself when I saw the gameplay, but I've slowly gotten back into the "hyped" phase. I'm really surprised there hasn't been an open-world, Romero zombie game, it seems like it would sell like hotcakes to a nerd crowd.

And is it me, or has Eastern Europe been churning out a lot of good games in the past 6 years or so?

Edit: did some research, and it turns out that this is the Call of Juarez team. I really loved Call of Juarez 2, and hope that Dead Island has the same creative minds that were behind CoJ 2, not the meh-looking latest entry.

Bought it, and have played through quite a bit of it, both co-op and single. I'm surprised most by the weapon system, since there's a sort of Borderlands-lite RPG system to it, with the added ability of modding weapons by adding in extra weight, sharp objects or elemental damage. The pros and cons so far:

Pros:
-Combat. It's melee focused, but it's brutal and engaging. Timing a kick against a rushing zombie, knocking him to the ground and slicing his head off with a sickle is just too much fun.
-Great open world. It's got this sort of tragic beauty vibe to it, where you can see what people were doing right before the outbreak happened, and the few survivors you find around have interesting little stories and are sympathetic enough to do their quests for them, sometimes without even considering the rewards.
-Storytelling. This is kind of a two-sided thing. It seems like when the game stops talking, it's when the game is at its narrative peak. Sorta spoilers, but in one of the first missions, you're sent to a poolhouse to grab a key, and just when you open the gate to the pool, you see a guy in the middle of the half-empty pooled stained in blood, surrounded by his slain family. This actually paused me for a second because of the way it was portrayed. This happened a few times for me, but these moments don't happen enough compared to the story's cons.

Cons:
-Story. I figured the trailer would get everyone's hopes too high, so I backed off a little on my hype, but even then I'm disappointed. Each character you can choose has an interesting back-story, but there is absolutely nothing in the way of character development beyond their bios in the select screen. The only lines I hear the main characters speak are in the form of zingers during combat. It just makes me feel like I'm playing a hollow little shell playing errand boy for everyone.
-Some of the combat has wonkiness. It has that problem with melee that a lot of first-person games have, where if an enemy is too close, and too low, you sometimes can't hit them, letting them get in a few cheap strikes. Melee range also seems unclear, because for some reason my diving knife can barely hit anything farther away than my nose, but the meat clever can hit way beyond my visible reach. Minor nitpicks, though, they don't really hurt the game.
-Quest tracking is kind of a pain in the ass. You can be walking down a path with a clear shot at the objective, then strafe to the left by a foot, and all of a sudden it wants you to circle around the island five times in order to get to your destination. Often times, the game will also present you with a quest that you can't perform until you open up new areas later on in the game, but it since it doesn't want to give out spoilers, you're stuck guessing when you're supposed to complete it. Another minor nitpick is sometimes when a quest-giver wants you to collect a common item such as canned food, they will sometimes not recognize the items that you collected before giving you the quest, but will accept them anyway, so if I give some guy all of my water, he won't give me my reward, forcing me to look for more stuff.

Overall, I'm enjoying the game, especially in co-op. It's a lot of fun to play, and you're usually rewarded pretty well for exploration, I'm just kind of disappointed that someone put so much effort into that trailer with the possibility of a good zombie game with an excellent fell so far short in the main plot area.

Alright, some complaints about co-op (playing both with people I personally know, and random XBL folks):

-Everyone go into your settings and fix your privacy settings so that you can speak to everyone, not just your friends. This is becoming incredibly common online in every game I play.

-Stick together. When more people are added, zombies are more powerful, and their numbers are increased. One person can't handle all of this.

-If a weapon is made for your character, and it looks decent enough, just grab it. Got sick of waiting for someone looking at a weapon on the ground, and comparing it to every weapon in their inventory.

-The blade chick has an insta-kill stomp (not sure about the others), but it gets interrupted every time you helplessly wail a corpse around. If you see someone playing as the Chinese woman trying to kick a downed zombie's head, just find something else to do.

More things I like:
-The city definitely picks things up. There's always tension about where enemies are, and where they're coming from.

-When you get a coordinated team, co-op is a blast.

-Exploring and rescuing random survivors always feels rewarding, as there's always a nice pay-off, and it helps to making you feel like you're making a difference in a completely fucked situation.

I know, doing a co-op RPG has to be a difficult thing to plan. Even when you have enemies and inventories balanced out, you still have to deal with differing quests with each character.

As it stands, the game is very fun, but at times I wish it had just been intended as single-player. Something about the way everything is done just makes me feel like I'm only half-playing the game in single-player, but then i fire up co-op and those frustrations begin. I think I'm done with the co-op unless my buddy and I just make dedicated characters to play online with each other.